Temporal context discrimination in patients with schizophrenia: associations with auditory hallucinations and negative symptoms.

BACKGROUND: A deficit in remembering the temporal context of events (a type of source memory) has been observed in schizophrenia, and suggested to be associated with positive symptoms.
METHODS: In order to investigate memory for temporal context, we administered a list discrimination task to a sample of schizophrenia patients and a sample of healthy controls. Participants were required to learn two lists of mixed high- and low-frequency words separated by 10 min, then to remember whether each word had been presented in the first or in the second list.
RESULTS: The number of misattributions to the wrong list was significantly higher in patients than in healthy controls. However, the group difference was eliminated when recall efficiency was covaried. The number of list misattributions was higher in patients with auditory hallucinations than in the other patients, independently of verbal recall efficiency. By contrast, affective flattening and anhedonia were associated with fewer list misattributions of the high-frequency words.
CONCLUSIONS: It is suggested that auditory hallucinations are associated with deficit in processing or remembering the temporal context. Conversely, certain negative symptoms are associated with reduced temporal context errors. The possible neural mechanisms involved in temporal context deficit as well as in these specific clinical symptoms are discussed.